From 76db8087c4c991dcd17f5ea8ac0eafd0696ab450 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Wed, 21 Mar 2018 16:31:04 -0700 Subject: net: bpf: add a test for skb_segment in test_bpf module Without the previous commit, "modprobe test_bpf" will have the following errors: ... [ 98.149165] ------------[ cut here ]------------ [ 98.159362] kernel BUG at net/core/skbuff.c:3667! [ 98.169756] invalid opcode: 0000 [#1] SMP PTI [ 98.179370] Modules linked in: [ 98.179371] test_bpf(+) ... which triggers the bug the previous commit intends to fix. The skbs are constructed to mimic what mlx5 may generate. The packet size/header may not mimic real cases in production. But the processing flow is similar. Signed-off-by: Yonghong Song Signed-off-by: David S. Miller --- lib/test_bpf.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 91 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/test_bpf.c b/lib/test_bpf.c index 3e9335493fe4..b2badf6b23cd 100644 --- a/lib/test_bpf.c +++ b/lib/test_bpf.c @@ -6574,6 +6574,93 @@ static bool exclude_test(int test_id) return test_id < test_range[0] || test_id > test_range[1]; } +static __init struct sk_buff *build_test_skb(void) +{ + u32 headroom = NET_SKB_PAD + NET_IP_ALIGN + ETH_HLEN; + struct sk_buff *skb[2]; + struct page *page[2]; + int i, data_size = 8; + + for (i = 0; i < 2; i++) { + page[i] = alloc_page(GFP_KERNEL); + if (!page[i]) { + if (i == 0) + goto err_page0; + else + goto err_page1; + } + + /* this will set skb[i]->head_frag */ + skb[i] = dev_alloc_skb(headroom + data_size); + if (!skb[i]) { + if (i == 0) + goto err_skb0; + else + goto err_skb1; + } + + skb_reserve(skb[i], headroom); + skb_put(skb[i], data_size); + skb[i]->protocol = htons(ETH_P_IP); + skb_reset_network_header(skb[i]); + skb_set_mac_header(skb[i], -ETH_HLEN); + + skb_add_rx_frag(skb[i], 0, page[i], 0, 64, 64); + // skb_headlen(skb[i]): 8, skb[i]->head_frag = 1 + } + + /* setup shinfo */ + skb_shinfo(skb[0])->gso_size = 1448; + skb_shinfo(skb[0])->gso_type = SKB_GSO_TCPV4; + skb_shinfo(skb[0])->gso_type |= SKB_GSO_DODGY; + skb_shinfo(skb[0])->gso_segs = 0; + skb_shinfo(skb[0])->frag_list = skb[1]; + + /* adjust skb[0]'s len */ + skb[0]->len += skb[1]->len; + skb[0]->data_len += skb[1]->data_len; + skb[0]->truesize += skb[1]->truesize; + + return skb[0]; + +err_skb1: + __free_page(page[1]); +err_page1: + kfree_skb(skb[0]); +err_skb0: + __free_page(page[0]); +err_page0: + return NULL; +} + +static __init int test_skb_segment(void) +{ + netdev_features_t features; + struct sk_buff *skb, *segs; + int ret = -1; + + features = NETIF_F_SG | NETIF_F_GSO_PARTIAL | NETIF_F_IP_CSUM | + NETIF_F_IPV6_CSUM; + features |= NETIF_F_RXCSUM; + skb = build_test_skb(); + if (!skb) { + pr_info("%s: failed to build_test_skb", __func__); + goto done; + } + + segs = skb_segment(skb, features); + if (segs) { + kfree_skb_list(segs); + ret = 0; + pr_info("%s: success in skb_segment!", __func__); + } else { + pr_info("%s: failed in skb_segment!", __func__); + } + kfree_skb(skb); +done: + return ret; +} + static __init int test_bpf(void) { int i, err_cnt = 0, pass_cnt = 0; @@ -6632,9 +6719,11 @@ static int __init test_bpf_init(void) return ret; ret = test_bpf(); - destroy_bpf_tests(); - return ret; + if (ret) + return ret; + + return test_skb_segment(); } static void __exit test_bpf_exit(void) -- cgit v1.2.3-58-ga151